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swadhinbiswas build: add licensing policy audit, eslimit size budgets, UMD bundler, and Go-powered esbuild build system · 7/23/2026
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Codec Licensing & Software Decoder Guardrails Policy

Overview & Scope

media-runtime is built on a strict hardware-first, zero-copy architecture. To protect downstream integrators and the media-runtime ecosystem from patent licensing claims and royalty exposure, this repository enforces explicit guardrails around software/WASM decoders and encoders.

1. Hardware-Only Codecs (Strictly Prohibited in WASM/Software)

The following codecs belong to patent licensing pools (such as MPEG-LA, Via Licensing, Velos Media, Access Advance, etc.) and MUST NEVER be compiled or distributed as WASM software decoders/encoders in @media-runtime/* packages:

  • H.264 / AVC (avc1.*)
  • H.265 / HEVC (hev1.*, hvc1.*)
  • AC-3 / Dolby Digital
  • E-AC-3 / Dolby Digital Plus
  • DTS / DTS-HD

Mandatory Decoder Resolution Strategy for Patented Codecs:

  1. WebCodecs API (VideoDecoder.isConfigSupported, AudioDecoder) using underlying OS/hardware decoders.
  2. Native HTML5 <video> / Media Source Extensions (MSE) hardware acceleration.
  3. If hardware decoding is unsupported by the OS/browser device, media-runtime will cleanly reject playback with a typed capability error (CODEC_HARDWARE_UNSUPPORTED).

2. Royalty-Free Codec Allow-list for Software/WASM Fallbacks

Software decoders implemented in WASM or TypeScript are strictly limited to royalty-free / open codecs:

  • AV1 (av01.*) - AOMedia Video 1
  • VP8 (vp8) - WebM / Google
  • VP9 (vp09.*) - WebM / Google
  • Opus (opus) - IETF / Xiph.Org
  • FLAC (flac) - Xiph.Org
  • Vorbis (vorbis) - Xiph.Org
  • Theora (theora) - Xiph.Org
  • Uncompressed PCM / Wave (pcm-u8, pcm-s16le, pcm-f32le)

3. Automated CI Enforcement (check-licensing.js)

A continuous integration lint rule (scripts/check-licensing.js) scans all committed files and compiled artifacts. Build pipelines will immediately fail if:

  • Any software decoder implementation targeting a non-allow-listed codec is detected.
  • Any WASM file is placed in packages/codecs without explicit inclusion in the royalty-free allow-list.

4. Optional FFmpeg Fallback Plugin

If an integrator explicitly chooses to opt into FFmpeg WASM for legacy offline software decoding in an environment they license independently, @media-runtime/codec-ffmpeg-fallback is isolated in a separate optional package. It emits a prominent runtime console warning detailing bundle size impact and patent licensing obligations.